Evaluating the Long-Term Safety and Tolerability of Efgartigimod PH20 SC Administered Subcutaneously in Patients With Generalized Myasthenia Gravis

The purpose of this study is to evaluate the long-term safety and tolerability of efgartigimod PH20 SC 1000 mg, and the clinical efficacy, PD, pharmacokinetics (PK), immunogenicity, impact on the quality of life (QoL) of the participants, treatment satisfaction, and administration method preference, and the feasibility of self- and caregiver-supported administration of the SC injection. Treatment duration: 3-week treatment periods, repeated as needed with at least 28 days in between treatment periods Health measurements: total levels of immunoglobulin G (IgG), Acetylcholine receptor binding autoantibodies (AChR-Ab) levels, Myasthenia Gravis Activities of Daly Living (MG-ADL).